Automatic Lock for Cargo Container

ABSTRACT

An automatic lock affixed to a cargo container for interconnecting two stacked containers, and for automatically locking and unlocking without reliance upon the overcoming of a friction force to release the device.

This application is a continuation of U.S. application Ser. No.14/452,019, filed Aug. 5, 2014, which claims the benefit of U.S.Provisional Application Ser. No. 61/862,310, filed Aug. 5, 2013.

BACKGROUND OF THE INVENTION

The present invention relates to the interlocking of stacked cargocontainers and, more particularly, to automatic locks which are securedto and travel with the container.

The prior art includes various devices for interconnecting stacked cargocontainers. These devices include manual locks, semi-automatic locks,and automatic locks. As will be recognized to those skilled in the art,manual locking devices must be manually installed within the cornerfitting, are manually locked, are manually unlocked, and are thenmanually removed from the corner fitting. Semi-automatic devices must bemanually installed in the corner fitting, provide automatic locking butmust be manually unlocked, and are then manually removed from the cornerfitting. Finally, automatic devices must be manually installed in thecorner fitting, provide automatically locking and unlocking, and arethen manually removed from the corner fitting.

Although the art has advanced from manual locks to semi-automatic locksto automatic locks, and although each new design has provided certainadditional benefits, today's fully automatic locks still have certaindrawbacks. First, many prior art automatic locks still require anoperator to manually install and remove the device from the cornerfitting of the container, resulting in additional time and cost duringloading/unloading. Second, many prior art automatic devices are designedto release once a predetermined friction force is overcome duringhoisting of the container. Due to such factors as tolerances, wear andabuse of the corner fittings, designs which rely upon release offriction forces can provide inconsistent results.

There is therefore a need in the art for an automatic lock which iscapable of interconnecting two stacked containers, and of locking andunlocking without reliance upon the overcoming of a friction force torelease the device. The same automatic lock is preferably affixed to thecontainer, thereby eliminating the need to install and remove suchdevice during loading/unloading of the container.

SUMMARY OF THE INVENTION

The present invention, which address the needs of the prior art,provides an automatic lock for a cargo container. The container has anupper surface and a lower surface. The lower surface defines a plane P.The container further includes at least one lower corner fitting locatedon the lower surface thereof. The lock includes a corner fittingmechanism sized and configured for location within an opening formed inthe lower corner fitting. The mechanism includes a lower cone sized andlocated to releasably engage an adjacent corner fitting when thecontainer is stacked upon another cargo container. The lock furtherincludes a rack having first and second ends. The first end of the rackis connected to the corner fitting mechanism whereby movement of therack actuates the corner fitting mechanism to move the lower conebetween a released unengaged position and a locked engaged position. Thesecond end of the rack extends outward from the lower corner fitting.The lock further includes a first linkage having first and second ends.The first end of the first linkage is pivotably connected to the secondend of the rack. The lock further includes a foot. The second end of thefirst linkage is pivotably connected to the foot. The lock furtherincludes a second linkage having first and second ends. The first end ofthe second linkage is pivotably connected to the foot. The secondlinkage is spring-loaded. The lock further includes a mounting pointaffixed to the lower surface of the container. The second end of thesecond linkage pivotably connected to the mounting point. The first andsecond linkages are sized and located such that the foot is suspendedbelow plane P prior to the stacking of the cargo container on anothercargo container whereby the contact of the foot with the upper surfaceof another cargo container causes upward movement of the foot and theresultant movement of the first linkage and of the rack therebyresulting in the actuation of the corner fitting mechanism.

As a result, the present invention provides an automatic lock which iscapable of interconnecting two stacked containers, and of locking andunlocking without reliance upon the overcoming of a friction force torelease the device. This same automatic lock is preferably affixed tothe container, thereby eliminating the need to install and remove suchdevice during loading/unloading of the container.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a typical well car having two 53′domestic cargo containers stacked thereon;

FIG. 2 is a schematical representation of the corner fittings of adomestic cargo container interacting with the retainers located on thefloor of a well car;

FIG. 3 is a schematical end view of a well car showing two stackeddomestic cargo containers;

FIG. 4 is a perspective view of a typical well car having a 53′ domesticcargo container stacked upon a 40′ ISO cargo container;

FIG. 5 is a schematical end view of a well car showing a domestic cargocontainer stacked upon an ISO cargo container;

FIG. 6 is a perspective view showing the automatic lock of the presentinvention;

FIG. 7 is a side elevation view showing an upper domestic cargocontainer incorporating the automatic lock of the present inventionbeing landed upon a lower domestic cargo container;

FIG. 8 is a view similar to FIG. 7 showing the upper domestic cargocontainer landed upon the lower domestic cargo container;

FIG. 9 is an enlarged detail of the automatic lock of FIG. 6, with thecorner fitting removed for clarity;

FIG. 10 is a view taken along arrow A of FIG. 6;

FIG. 11 is a view taken along arrow B of FIG. 6;

FIG. 12 is a view showing the orientation of the components of theautomatic lock of the present invention when the upper cargo containerhas been landed;

FIG. 13 is a view taken along arrow C of FIG. 12;

FIG. 14 is a cross-sectional view taken along lines D-D of FIG. 12;

FIG. 15 is a detail of the cam/cam follower arrangement of the automaticlock of the present invention;

FIG. 16 is a sectional view taken through the corner fitting mechanismof the automatic lock of the present invention;

FIG. 17 is a schematical top view of the cam/cam follower arrangement ofthe automatic lock of the present invention;

FIG. 18 is a flat pattern of the cam's profile and cam followerposition, synchronized in time;

FIG. 19 is another sectional view taken through the corner fittingmechanism of the automatic lock of the present invention; and

FIG. 20 is a schematical view showing the interaction of one cornerfitting of a domestic cargo container incorporating the automatic lockof the present invention with a retainer positioned on the floor of awell car.

DETAILED DESCRIPTION OF THE INVENTION

It is commonplace in the rail industry to use what are commonly referredto as well-cars (also known as double-stack cars) to transport cargocontainers. A typical well-car 10 is shown in FIG. 1. A lower container12 sits within the well of the car, while an upper container 14 restsupon lower container 12. Those skilled in the art will recognizecontainers 12, 14 to be 53′ U.S. Domestic Containers, which is a commoncontainer used in the rail industry. These 53′ containers are all madewith a standard size and configuration, including the location of fourcorner fittings on both the upper and lower surfaces.

Referring now to FIG. 2, each of containers 12, 14 is formed with astandard width of 8′-6″. As best seen in FIG. 1, the corner fittings arelocated at the outer edges of the container, such that the distance fromthe outer edge of corner fitting 16 a to the outer edge of cornerfitting 16 b is also 8′-6″. Each of the corner fittings located on thelower surface of a domestic container is formed with both an outboardopening 18 and an inboard opening 20. Located at the bottom of eachwell-car are four retainers 22, which are sized and located to engageand penetrate the inboard openings of the four corner fittings locatedon the bottom surface of container 12 when container 12 is lowered intothe well of car 10. The combination of retainers 22 and the walls of thewell-car ensure that container 12 is secure for transport. When a secondcontainer, e.g., container 14, is to be stacked upon container 12, it isindustry practice today to use a plurality of twistlocks to interconnectand lock container 14 to container 12.

The stacking of two 53′ domestic containers is best illustrated withreference to FIG. 3. As shown, retainers 22 affixed to the bottom ofwell car 10 penetrate inboard openings 20 in each of the four cornerfittings located on the bottom surface of container 12. The outboardopenings 18 located in these same corner fittings are not used in thisapplication. Four twistlocks 24 are then used to interconnect and lockcontainer 14 to container 12.

The rail industry also uses 8′ wide containers referred to as ISOstandard containers. These ISO standard containers can be formed withlengths of 10′, 20′, 30′, 40′ and 49′. A 40′ ISO container 26 is shownin FIG. 4. As shown, container 26 is positioned within the well of car10. A 53′ domestic container 28 is stacked thereon. This stackedrelationship is best illustrated with reference to FIG. 5. Asillustrated in FIG. 5, container 26 includes a plurality of cornerfittings 30, all of which are formed with a single opening 32. Openings32 are located to engage retainers 22 in the same manner that openings20 of fittings 16 engaged retainers 22. A plurality of twistlocks 24 areused to interconnect and lock container 28 to container 26. Inasmuch ascontainer 26 is narrower in profile, inboard openings 20 of cornerfittings 16 receive one of the locking cones of the twistlocks. In thisapplication, outboard openings 18 of corner fittings 16 are not used.

It has been discovered herein that the dual opening configuration of thecorner fittings on the lower surface of domestic containers can beutilized in the design of an automatic lock for such containers. Moreparticularly, the present invention provides a novel automatic lockingsystem which can be installed on the lower surface of a domesticcontainer, and which will cooperate with the outboard opening of eachcorner fitting located on such lower surface. As will be explainedfurther hereinbelow, such an arrangement still allows the domesticcontainer to be used in the applications described above. Moreparticularly, the novel arrangement of the present invention will notinterfere with retainers 22 of well-car 10 engaging inboard openings 20of corner fittings 16 when the domestic container is placed within thewell of car 10. In such a scenario, the novel locking arrangement of thepresent invention will simply remain unused. In the arrangement shown inFIG. 5, the novel locking arrangement of the present invention will alsoremain in unused condition without interfering with the usage of fourtwist locks to interconnect and lock container 28 to container 26.However, in the common application shown in FIG. 3 (wherein a domesticcontainer is stacked upon another domestic container), the novelautomatic locking arrangement of the present invention will eliminatethe need for twistlocks 24, thus saving time and money during loadingand unloading of the containers.

An automatic lock 100 formed in accordance with the present invention isshown in FIG. 6. Lock 100 includes a corner fitting mechanism 102, arack 104, a linkage 106, a foot 108, and a spring-loaded linkage 110. Asshown, mechanism 102 is located within outboard opening 112 of cornerfitting 114. The other end of automatic lock 100, i.e., end 116 oflinkage 110, is pivotably connected to a mounting point 118 located onthe bottom of the same container including corner fitting 114. As willbe more fully understood with reference to FIG. 7, mounting point 118 islocated on the bottom surface of the container 120, container 120 beinga domestic container. Foot 108 extends downward below the plane, i.e.,plane P, defined by the bottom surface of corner fitting 144. Ascontainer 120 is lowered upon container 122 (also a domestic container),foot 108 contacts the upper surface 124 of container 122. The continuedlowering of container 120 causes foot 108 to move generally upward,which in turn moves linkage 106 and linkage 110. More particularly,movement of linkage 106 causes horizontal movement of rack 104 (to theleft as viewed in FIG. 7). As shown in FIG. 6, rack 104 extends througha flange 126, which restricts movement of rack 104 to a horizontal leftand right translation (as viewed in FIG. 7). The generally upwardmovement of foot 108 also causes spring-loaded linkage 110 to compress,thereby providing a biasing force tending to urge foot 108 downward toits “at-rest” position below the surface of plane P.

FIG. 8 shows domestic container 120 landed upon domestic container 122.Foot 108 remains in contact with upper surface 124 of lower container122. As such, foot 108 has been moved toward the bottom surface ofcontainer 120. This movement results in the translation of rack 104 tothe left, which in turn causes lower cone 128 to move into its lockingposition within corner fitting 130 of container 122. The movement offoot 108 also causes spring-loaded linkage 110 to compress into thebiased position shown in FIG. 8. When upper container 120 is unloaded,the action is reversed—that is, spring-loaded linkage 110 moves foot 108downward, which in turn moves linkage 106, and ultimately rack 104 tothe right (as viewed in FIG. 8). It is further contemplated herein thatfoot 108 may be replaced with a spherical-shaped joint, which may bemore resistant to inadvertent impact forces encountered during handlingof the container.

To better illustrate the operation of mechanism 102, corner fitting 114has been removed from FIG. 9. Like FIG. 8, FIG. 9 shows lock 100 in itslocked orientation. That is, foot 108 has been moved upward,spring-loaded linkage 110 has been moved into a biased position, andrack 104 has been translated to its left-most orientation. Lower cone128 is shown in its rotated and locked orientation. In addition to lowercone 128, corner fitting mechanism 102 includes a housing body 132, aslider 134, and a gear 136. As shown in FIG. 6, housing body 132preferably includes a front body portion 132 a and a rear body portion132 b. As will be more fully explained hereinbelow, the movement of rack104 to the left causes rotation of gear 136, which in turn causesvertical translation downward of slider 134, as well as both verticaland rotational movements of lower cone 128. Referring back now to FIG.8, slider 134 is shown extended downward into corner fitting 130, andlower cone 128 is rotated to engage at least a portion of corner fitting130.

In FIG. 10, rear body portion 132 b has been removed for clarity. Asshown, a spline shaft 138 extends through and engages gear 136. As aresult, rotation of gear 136 causes simultaneous rotation of shaft 138.Shaft 138 is preferably an integral component which extends through gear136 into engagement with lower cone 128 such that rotation of shaft 138causes simultaneous rotation of lower cone 128. A pair of cam followers140 a, 140 b are secured to opposing sides of spline 138, and follow camsurfaces 142 a, 142 b formed in body portions 132 a, 132 b,respectively. As will be explained more fully hereinbelow, the loweredges of body portions 132 a, 132 b include skirts 144. Skirts 144extend around all four sides of mechanism 102.

Referring back to FIG. 7, in one preferred embodiment mechanism 102 isconfigured such that lower cone 128 is located outside of corner fitting114, even when in the “at-rest” condition. This design recognizes thelimited vertical height within corner fitting 114, as well as the needto vertically displace lower cone 128 downward into engagement with thecorner fitting on the container therebelow. FIG. 11 (which is a viewtaken along arrow B of FIG. 6) shows lower cone 128 in its “at-rest”position. This will also be the position of lower cone 128 when acontainer has been hoisted for loading. As mentioned hereinabove, lowercone 128 is connected to spline shaft 138. Moreover, lower cone 128translates vertically downward together with slider 134. As a result,lower cone 128 is rotating at the same time it is being displaceddownward. To ensure that lower cone 128 will be in a suitableorientation to allow passage through the opening in the corner fittingof the lower container, lower cone 128 is initially positioned in theorientation in FIG. 11. Thus, lower cone 128 can rotate throughapproximately 61 degrees from the initiation of translation to the pointwhere lower cone 128 is within the corner fitting of the lowercontainer. Once inside the corner fitting in the lower container,continued rotation of lower cone 128 will cause lower cone 128 to engagea portion of the corner fitting, thereby interconnecting the upper andlower containers.

Referring now to FIG. 12, mechanism 102 further includes a verticalspring 146. Spring 146, which functions to urge cam followers 140 a, 140b into engagement with cam surfaces 142 a, 142 b, will be describedfurther hereinbelow. In one preferred embodiment, the vertical stroke ofslider 134 is approximately 1⅜ inches. The orientation of lower cone 128when in the fully rotated position is shown in FIG. 13. As mentionedhereinabove, lower cone 128 rotates through approximately 61 degrees ofrotation as it translates downward to penetrate the corner fitting inthe lower container. As shown, once inside the corner fitting of thelower container, lower cone 128 continues rotating counterclockwise (asviewed in FIG. 13) approximately 15° such that bearing area 148 engagesthe corner fitting of the lower container. In one preferred embodiment,bearing area 148 provides the minimal bearing contact area of 400 mm².Depending on the size and configuration of lower cone 128, more or lessrotation may be required to obtain the minimum bearing contact area. Isalso contemplated herein that bearing area 148 may be configured tofacilitate release of the lower cone from the lower corner fittingduring unloading of the upper container. More particularly, bearing area148 may be formed with a cross-sectional configuration which tends torotate lower cone 128 in the clockwise direction (as viewed in FIG. 13)in the event that hoisting of the upper container causes lower cone 128to contact the inner surface of the lower corner fitting.

Cam surfaces 142 a, 142 b and cam followers 140 a, 140 b will beexplained in greater detail with reference to FIGS. 14-16. Turning firstto FIG. 14, cam followers 140 a, 140 b are rotatably connected to splineshaft 138 via shafts 150 a, 150 b, respectively. As best seen in FIG.15, as spline shaft 138 rotates clockwise, cam follower 140 b willtravel along cam surface 142 b. Simultaneously, cam follower 140 a willtravel along cam surface 142 a. Referring now to FIG. 16, one end ofvertical spring 146 extends within spline shaft 138, while the other endextends upward to contact the interior floor of the upper container.More particularly, spring 146 is arranged to contact a fixed surface ofthe upper cargo container such that spring 146 maintains a downwardbiasing force against shaft 138. This downward biasing force will ensurethat the cam followers remain in contact with the cam surfaces as splineshaft 138 is rotated. As best seen in FIG. 16, shaft 138 includes ashoulder 152. Slider 134 is accordingly captured between shoulder 152and lower cone 128. As a result, vertical displacement of spline shaft138 causes simultaneous vertical displacement of slider 134. Splineshaft 138 is also free to rotate with respect to slider 134 as it isvertically displaced. Due to the size limitations of the corner fitting,a portion of spline shaft 138 preferably extends above the height ofgear 136 (see FIG. 10), such portion extending into opening 154 of thecorner fitting shown in FIG. 16. As a result, vertical spring 146 ispreselected to have a length which extends through this same opening andcontacts interior floor 156 of the container. Of course, is contemplatedherein that vertical spring 146 could be configured to contact anotherfixed area of the corner fitting and/or upper cargo container.

FIGS. 17-18 provide further details regarding the cam/cam followerarrangement of the present invention. FIG. 17 provides a schematicalcross-sectional view showing the connection of the cam followers to thespline shaft, as well as the front and rear cam surfaces. FIG. 18 is aflat pattern of the cam's profile, together with the cam followerposition, synchronized in time. The front and rear patterns aresubstantially identical. At 0° (i.e., the initial position), the slideris an upper position. Vertical spring 146 is fully compressed betweeninterior floor 156 and the contact surface within the spline shaft. Theforce exerted by spring 146 forces each of the cam followers intocontact with their respective cam surfaces. At this point, foot 108begins to contact a surface therebelow, e.g., the upper surface of alower domestic container. From 0° to 5°, the upper domestic container islowered downward. This in turn causes generally upward displacement offoot 108, which in turn causes movement of the rack (to the left isviewed in FIG. 12), and in turn rotation of gear 136. During this first5° of rotation, downward translation of slider 134 is preferablyrestricted. The restriction of downward movement of slider 134 duringthis first 5° of rotation limits/eliminates unwanted movement of the camfollowers due to vibrations/forces encountered at the initiation oflanding, e.g., forces generated by the initial compression ofspring-loaded linkage 110. From 5° to an angle β=61°, the slider movesdown, and the lower cone rotates in the clockwise direction (as viewedfrom above). Once angle β has been reached, lower cone 128 haspenetrated the opening in the lower corner fitting and is positioned forlocking rotation. During the same time, foot 108 has been translatedupward, and spring-loaded linkage 110 has been compressed. The 61° anglementioned above corresponds to the 61° angle discussed with reference toFIG. 11. Depending on the configuration and design, this 61° angle maybe increased or decreased. From angle β to 97°, the landing of the uppercargo container continues. During this time, the slider is in its lowestposition, and lower cone 128 continues to rotate. From 97° to 120°, thelower cone rotates to its locked position, i.e., to provide the requiredbearing surface contact area. At 120°, the landing of the upper cargocontainer has been accomplished.

Referring now to FIG. 19, and as mentioned hereinabove, body 132 isformed with a plurality of skirts 144 about its lower edges (see FIG.10). Skirts 144 interact with chamfered edges 158 of the opening in thecorner fitting. As such, mechanism 102 can be inserted into the openinguntil skirts 144 contact chamfered edges 158. It will be appreciatedthat this contact occurs on all four sides of mechanism 102, thuslimiting any movement of mechanism 102 with respect to the cornerfitting, other than downward vertical movement. To secure mechanism 102within the corner fitting, a plurality of wedges 160 are employed. Asshown, two wedges are attached on each side of mechanism 102 viaclamping screws 162. Wedges 160 are preferably formed with a conicalshape such that tightening of screw 162 forces the individual wedge intogreater contact with the interior surface of the corner fitting, thusurging mechanism 102 vertically upward, while at the same time fixedlysecuring mechanism 102 therein.

FIG. 20 shows a corner fitting of a domestic container containing theautomatic lock of the present invention interacting with a retainerpositioned on the floor of a well-car. As discussed hereinabove, theretainers located on the floor of the well-car penetrate and engage theinboard openings of the lower corner fittings. Plate 164, which supportsretainer 22, typically has a thickness of approximately ½ inch. In onepreferred embodiment, lower cone 128 is designed to extend approximately½ inch below the surface of the corner fitting. As a result, the cargocontainer will rest upon plates 164, and not upon lower cone 128.

It is contemplated herein that a domestic container containing theautomatic lock of the present invention may be landed on the ground. Inthis situation, the weight of the container will rest upon the fourlower cones protruding from the lower corner fittings. The novel designof the current automatic lock ensures that the mechanism fitted withineach corner fitting can support the weight of the container. In additionto the domestic containers described hereinabove, it is contemplatedherein that the automatic lock of the present invention may be utilizedwith other standard containers used in the different forms of cargotransportation.

It will be appreciated that the present invention has been describedherein with reference to certain preferred or exemplary embodiments. Thepreferred or exemplary embodiments described herein may be modified,changed, added to or deviated from without departing from the intent,spirit and scope of the present invention, and it is intended that allsuch additions, modifications, amendments and/or deviations be includedin the scope of the present invention.

What is claimed is:
 1. An automatic lock for a cargo container, saidcontainer having an upper surface and a lower surface, said containerfurther including at least one lower corner fitting located on saidlower surface thereof, comprising: a corner fitting mechanism sized andconfigured for location within an opening formed in said lower cornerfitting, said mechanism including a lower cone sized and located toreleasably engage an adjacent corner fitting when said container isstacked upon another cargo container; a rack having first and secondends, said first end of said rack connected to said corner fittingmechanism whereby movement of said rack actuates said corner fittingmechanism to move said lower cone between a released unengaged positionand a locked engaged position, said second end of said rack extendingoutward from said lower corner fitting for actuation thereof; and aflange secured with respect to said lower corner fitting for restrictingmovement of said rack to a predetermined linear direction.
 2. The lockaccording to claim 1, wherein said corner fitting mechanism furtherincludes a housing body, a gear and a spline shaft; and wherein saidhousing body supports said gear, an outer surface of said gear engagingsaid first end of said rack, said spline shaft engaging an inner surfaceof said gear whereby rotation of said gear causes simultaneous rotationof said spine shaft, said spline shaft engaging said lower cone wherebyrotation of said spline shaft causes simultaneous rotation of said lowercone.
 3. The lock according to claim 2, wherein said corner fittingmechanism further includes a pair of cam followers and a verticalspring, and wherein said housing body includes opposing cam surfaces;and wherein said vertical spring causes said cam followers to followsaid cam surfaces as said spline shaft is rotated whereby said splineshaft is simultaneously vertically displaced upon rotation thereof bysaid gear.
 4. The lock according to claim 3, wherein said corner fittingmechanism further includes a slider, said slider cooperating with saidspline shaft whereby vertical displacement of said spline shaft causessimultaneous vertical displacement of said slider; and wherein saidspline shaft rotatably extends through said slider.
 5. The lockaccording to claim 4, wherein said lower corner fitting includes both aninboard opening and an outboard opening; and wherein said corner fittingmechanism is located in said outboard opening of said lower cornerfitting.
 6. The lock according to claim 5, wherein said housing bodyincludes a plurality of skirts configured to engage the circumference ofthe opening of said outboard opening of said lower corner fitting. 7.The lock according to claim 6, further comprising a plurality of wedgesfor securing said corner fitting mechanism within said outboard openingof said lower corner fitting.
 8. The lock according to claim 7, whereinsaid lower cone extends approximately ½ inch below a lower surface ofsaid lower corner fitting.
 9. An automatic lock for a cargo container,said container having an upper surface and a lower surface, saidcontainer further including at least one lower corner fitting located onsaid lower surface thereof, comprising: a corner fitting mechanism sizedand configured for location within an opening formed in said lowercorner fitting, said mechanism including a lower cone sized and locatedto releasably engage an adjacent corner fitting when said container isstacked upon another cargo container, said mechanism further including ahousing body, a gear and a spline shaft; and wherein said housing bodysupports said gear, said spline shaft engaging a surface of said gearwhereby rotation of said gear causes simultaneous rotation of said spineshaft, said spline shaft engaging said lower cone whereby rotation ofsaid spline shaft causes simultaneous rotation of said lower cone. 10.The lock according to claim 9, wherein said corner fitting mechanismfurther includes a pair of cam followers and a vertical spring, andwherein said housing body includes opposing cam surfaces; and whereinsaid vertical spring causes said cam followers to follow said camsurfaces as said spline shaft is rotated whereby said spline shaft issimultaneously vertically displaced upon rotation thereof by said gear.11. The lock according to claim 10, wherein said corner fittingmechanism further includes a slider, said slider cooperating with saidspline shaft whereby vertical displacement of said spline shaft causessimultaneous vertical displacement of said slider; and wherein saidspline shaft rotatably extends through said slider.
 12. The lockaccording to claim 11, wherein said lower corner fitting includes bothan inboard opening and an outboard opening; and wherein said cornerfitting mechanism is located in said outboard opening of said lowercorner fitting.
 13. The lock according to claim 12, wherein said housingbody includes a plurality of skirts configured to engage thecircumference of the opening of said outboard opening of said lowercorner fitting.
 14. The lock according to claim 13, further comprising aplurality of wedges for securing said corner fitting mechanism withinsaid outboard opening of said lower corner fitting.
 15. The lockaccording to claim 14, wherein said lower cone extends approximately ½inch below a lower surface of said lower corner fitting.